Pain – Causes and Treatment

The word pain comes from the Latin poena which stands for punishment, as it was considered punishment from Gods.

In spite of continuous advances in medicine, it is a massive medical, economic, and societal problem even today. Fifty percent of emergency visits and 30% of family practice visits are attributed to pain.

Overview

Pain is defined as perception of the signals by body about occurring or potential tissue damage. The processes in the body that are involved in the perception of pain are called nociception. There are many mechanisms involved in nociception.

From the receptors on an electrical impulse that travels from to the spinal cord which acts like a relay center where the signal can be blocked, enhanced, or otherwise modified before forwarding to brain.

It involves an interplay between neurotransmitters which  are responsible for transmission of nerve impulses from one cell to another and part of it is linked directly with the emotional centers in the brain.

Our feelings like like anger, anxiety increase it and positive feeling like happiness make it less.

Classification of Pain

In terms of onset time, the pain can be acute or chronic.

Acute pain is of recent onset and generally is expected to be over soon. An example is a sprained ankle.

A pain that continues for a period of several months or longer, or occurs frequently for months is termed as chronic .  Backpain or arthritis are examples.

Depending upon its charecteristics, the pain may nociceptive, neuropathic or psychogenic.

Nociceptive

It is the pain caused by ongoing activation of pain receptors in either the surface or deep tissues of the body. It is of two types –  somatic and visceral

Examples are injury to skin, muscles, bone, joint, and connective tissues.

Visceral pain originates from injury to the visceral organs like gall bladder, intenstine, lungs etc. or the tissues that support them. It is poorly localized and cramping or could be pressure-like, deep, and stabbing in case of non hollow organs.

Neuropathic

This type of pain continues even after the injury has healed and believed to be caused by changes in the nervous system.

The cause could be trauma or diseases like diabetes. Diabetic neuropathy and complex regional pain syndromes are few examples.

Psychogenic

It stands for all kinds of pain for which the cause can be attributed to psychological problems. Most patients with chronic painful conditions have some degree of psychological issues like anxiety or depression.

Therefore patients with chronic painful conditions should be assessed for psychological factors, and psychological treatments should be considered an important aspect of pain therapy.

Diagnosis

Exact measurement of pain is not possible. In spite of medical advances, there is no test to measure intensity, no imaging device can show pain, no equipment for localization, though functional MRI (fMRI) is an advancement towards this.  fMRI brain scanning has been used to measure pain, giving good correlations with self-reported pain.

Physicians may use scales for assessment like FACES and VAS .

Best aid to diagnosis is the patient’s own description of the type, duration, and location of pain. e.g. sharp or dull, constant or intermittent, burning or aching may give the best clues to the cause.

Physician’s concern  is to find out underlying cause and provide treatment accordingly. To reach at the conclusion, depending upon the site and suspected ailment, lab investigations and imaging procedures like x-ray, ultrasound, CT scan or MRI, electromyography (EMG), nerve conduction studies, and evoked potential (EP) studies.

Special studies may be done in few cases. For example  discography to locate painful disc. Ongoing depression, anxiety, and substance abuse need to be identified.

Treatment

The treatment should be aimed at pain relief, improvement of function and return to activities of daily living and social activities.

Acute painful episode is usually managed with medications such as analgesics and anesthetics. Management of chronic pain, is much more difficult and may require team efforts of  medical practitioners, clinical psychologists, physiotherapists, occupational therapists, physician assistants, and nurse practitioners.

In an acute setting, pain is managed by

• Resting the affected part
• Application of heat or ice
• Nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, or naproxen; or acetaminophen

A secondary tier of treatments may include medications, nerve blocks, biofeedback, steroid injections, anticonvulsants and behavioral therapy

Drug Therapy

Analgesic Drugs

This group includes both opoid drugs like buprenorphine, tramadol, and non steroidal anti-inflammatory drugs like aspirin, , acetaminophen, and ibuprofen etc.

Non steroidal anti-inflammatory drugs act at the level of peripheral pain receptors, opoid drugs act at central level to decrease the perception of painful stimuli.

Anticonvulsants

Carbamazepine in particular is used to treat a number of painful conditions, including trigeminal neuralgia. Gabapentin also has a role in neural pains.

Antidepressants

Antidepressants or psychotropic drugs and anti-anxiety drugs are sometimes used  along with analgesicsin selected cases where simple analgesic therapy is not effective.

Local Applicants

Irritants like capsaicin work by increasing blood flow to the skin when applied locally. Increased blood flow provides warmth and sense of pain relief.

Antimigraine Drugs

sumatriptan, naratriptan , and zolmitriptan and are used specifically for migraine headaches.

Steroids

Steroids are potent analgesics and antiinflammatory agents. In musculoskeletal problems, intralesional streoids are often used to provide pain relief.

Biofeedback

Used most notably for  headache and backache, by using a special electronic machine, the patient is trained to become aware of, to follow, and to gain control over certain bodily functions, including muscle tension, heart rate, and skin temperature. The individual can then learn to effect a change in his or her responses to pain, for example, by using relaxation techniques.

Cognitive Behavioral Therapy

It consists of  wide variety of coping skills and relaxation methods to help prepare for and cope with pain. It is used for postoperative pain, cancer pain, and the pain of childbirth.

Counseling

It aims at providing and could be derived from family, group, or individual counseling. Support groups also serve the same purpose.

Electrical stimulation

Electrical stimulation can be given by various methods and each require specialized equipment and trained personnel.

TENS

It uses tiny electrical pulses, delivered through the skin to nerve fibers, tonumbness or contractions in the muscles and in turn produces temporary pain relief.

Peripheral Nerve Stimulation

Electrodes are placed surgically on a carefully selected area of the body using a remote device, patient can deliver an electrical current as needed.

Spinal Cord Stimulation

Electrodes are surgically inserted within the epidural space of the spinal cord. The patient is able to deliver a pulse of electricity to the spinal cord by using a device.

Deep brain stimulation

Surgical stimulation of the brain, usually the thalamus is used for a limited number of conditions, including severe pain, central pain syndrome, cancer pain, phantom limb pain, and other neuropathic pains.

Nerve Blocks

This method is used to interrupt the relay of pain messages between specific areas of the body and the brain.  The procedure could be done surgically drugs.

Neurectomy,  trigeminal rhizotomy and sympathectomy are few examples.

Physical Therapy and Rehabilitation

Light to moderate exercise such as walking or swimming-can contribute to well-being, can  help reduce stress, thereby helping to alleviate pain.

Local Therapies

R.I.C.E.-Rest, Ice, Compression, and Elevation-are prescribed by for temporary muscle or joint conditions, such as sprains or strains o rin setting of acute injury.

Surgery

Surgery is usually last resort if feasible and the option cannot be exercised in all kinds of pain.

Few examples are disecectomy,  joint fusion, ingrown toe nail removal etc.